1. Field of the Invention
The instant invention is broadly concerned with products molded to conform to the size and shape of a particular object and methods for producing these products. In preferred forms, the products of the invention are footwear products (such as shoes or boots) having substantially the same size and shape of the foot on which it is to be worn. Products of the invention are formed from moldable materials which stretch and shape easily, such as natural leathers, synthetic leathers, and mixtures thereof. In the methods of the invention, the moldable material is cut to a size and shape similar to that of the object around which it is to be molded. A mixture comprising a leather hardening or stiffening agent is then applied to the material. The resulting mixture-covered material is dried while remaining on the object, resulting in a form-fitting, molded product at a cost much lower than the cost of currently available custom-made products.
2. Description of the Prior Art
Animal hides or skins are preserved by a process called tanning wherein a chemical is applied to the hide or skin. This process makes the hide immune to bacterial attack, raises the shrinkage temperature of the hide, and prevents the collagen fibers from sticking together upon drying, resulting in a material that remains porous, soft, and flexible. Two widely used tanning methods include vegetable tanning and chrome tanning. With chrome tanning, the pickled hide is usually saturated with a solution of basic chrome sulfate, followed by precipitation of the chrome compound by adding a small quantity of a mild alkali. This results in a reaction of a coordination nature between the carboxyl groups of the skin collagen and the metal atoms. With vegetable tanning, heavy hides are given a series of baths in gradually increasing strengths of extracts containing tannic acid (tannins), such as quebrachro and wattle extracts. Molecular aggregates of the tannin within the hides form cross-links between the polypeptide chains of the hide proteins. Vegetable tanning produces a relatively dense leather that is pale brown in color and tends to darken upon exposure to natural light.
In the past, vegetable-tanned leather has rarely been used in footwear because it absorbs water and leather conditioner quickly, and it stretches and shapes too easily. Thus, prior art vegetable-tanned leather shoes would quickly stretch so that eventually they no longer fit the wearer's feet. This is particularly true when the vegetable-tanned leather is exposed to moisture.
Shoes, boots and other footwear have generally been made from chrome-tanned leather. While chrome-tanned leather doesn't absorb water or leather conditioners easily, it also doesn't shape easily. In the past however, chrome tanning has been the quickest and easiest way to tan leather. In the manufacturing process, shoes are built on lasts of varying sizes categorized by widths and lengths. The chrome-tanned leather is shaped over the last with heat and pressure, resulting in a shoe having a well-retained shape with little stretch remaining in the leather. If the shoe is too tight, the wearer oftentimes wears the shoe for a number of days or weeks in hopes of stretching the leather until a comfortable fit is obtained. This can be painful for the wearer as well as harmful to the wearer's feet. However, this method of manufacturing shoes is much more affordable than having shoes custom-made (which is very labor intensive) to the exact size and shape of the wearer's foot.